Process of and apparatus for reducing and smelting ores



.J. LUND. PROCESS OF AND APPARATUS FOR REDUCING AND SMEL'HNG ORES.

APPLICATION FILED JUNEZG. I916.

Patented Jan. 11, 1921.

4 SHEETSSHEET 1.

P. 0 ma N W L J" LUND.

PROCESS OF AND APPARATUS FOR REDUCING AND SMELTING ORES. APPLICATIONFILED JUNE 26, 1916.

1 35 1 13 Patented Jan. 11, 1921.

4 SHEETS-SHEET 3- J. LUND. PROCESS OF AND APPARATUS FOR REDUCING ANDSMELTING ORES.

" APPLICATION FILED JUNE 26. ms.

1-;365,113. Patented Jan. 11,1921.

4 SHEETS-SHEET 4.

.J. LII/VD cisco, in the county of'San UNITED STATES PATENT OFFICE.

JOEL mum, on san raaucisco, camroimm.

PROCESS AND APPARATUS FOR REDUCING AND SMELTING ORFS.

To all whom it ma y concern:

Be "it known that I, JOEL LUND a citizen of the United States, residinat San F ranrancisco and State of California, have invented new anduseful Improvements in Processes of and Apparatus for Reducing andSmelting Ores,

of which the following is a specification.

The object of the present invention is to provide a process of, andapparatus for, re-

ducing and smelting ores,by means of which ores can be reduced andsmelted continuously by the use of fluid fuel or finely divided solidfuel, and without the necessity of forming the ores into briquets. Afurther objectis to provide an apparatus for this purpose which willenable me to introduce fuels and gases under pressure for the purpose ofaccomplishing the above result and by which the gases so mtroduced maybe maintained in a reducing condition.

In the accompanying drawing, Figure 1 is a vertical section on the line1-1 of Fig. 2; Fig. 2 is a verticalsection on the line 2-2 of Fig. 1; Fi3 is a' broken side view of the apparatus; I ig. 4 is a broken end viewthereof; Fig. 5 is a horizontalsection thereof on the line 5-5 of Fig.2; Fig. 6 is a horizontal section on the line 6-6 of Fi 1; F i 7 is avertical section on the line --7 of ig. 2; Fig. 8 is an enlargedsectional view of a detail; Fig. 9 is a broken perspective view of adetail.

Referrin to the drawing, 1 indicates a conveyer o ordinary construction,by means of which ore is conveyed to a chamber in the upper portion ofan ore stack 3 divlded into compartments 2, 4, 6, 7 by a screen 8 andmovable slides 9, 11. Said ore stack container is preferably made ofsheet metal of sufiicient stren h to stand the pressure of the materialwlthin the same, as well as the gaseous pressure comin from a tubularreduction chamber '12.- T e sheet metal screen 8 is hinged in the top ofthe ore stack and is pressed forwardly against the side through.

which the conveyer' enters by a spring 13.

The object of said screen is to preventa too.

rapid escape of such compressedgases as may have collected in thechamber 6, ashere-Q inafter explained, when the shdell 1s open to permitmaterial to enter the compartment 7 Said gases are permitted'to escapegradually from the compartment 4 by the arrangement shown, the edges ofthe screen 8 not Specification of Letters Patent. P te ted Jan, 11,1921; Application filed June 26, 1916. Serial No. 105,859.

- fitting closely against the sides of the stack 3,

but against partitions 14, between which partitions and the sides of thestack are artitions 16, shown in dotted lines'in Fig. 1, formingchambers 17. .As said gases escape into the chambers 17 (Fig. 1) it willbe seen that whatever material may have been'carried with them willagain descend into compartment 6 when the slide 9 is closed.

Said slides are operated to close or open said compartment by wheels 18,(see F i 1 and 3), these being secured to nuts 19 w ich rotate inbrackets 21 and engage screws 22, which are secured to the slides 9, 11,so that, asthe wheels 18 are rotated by pulling on cables or chains 23around the. wheels, and the nuts-19 are rotated with the wheels, the

screws 22 move longitudinally therethrou gh and the slides 9, 11 areopened or closed. relieve the slides 9 and 11 of excessive friction andpressure, the openings closed by said slides are reduced in size by theinwardly converging projections 24 from'the sides of the ore chamber,between which said stationary cap 32, which is connected with awater-tight joint to a movable collar 33 secured to the tube 30, thepipe 29 extending within the screw to a short dlstance from its lowerend, and the pi e 31 conducting ofl the-water within the tu 30. On theupper end of the feed screw is secured a worm wheel 34, which is rotatedb means of a worm 36 on a shaft 37 (see carries a differential speedmechanism 38 driven b a motor (not shown). In a supporting racket 39 isformed a bearin in which the feed screw is fitted, and a ho low collar42 is filled with some resilient'refractor material 43, such as mineralwool, and

ig. 2 which is tted over the stem of the feed screw inside of thebearing to rotect the parts. f

" the entrance of grit. he bracket 39 is made iiof (ill

. its.

in sections, removable on opposite sides of the bearing, to facilitatethe positioning and removal of the screw when necessary.

A rotary device 150, turned by a weight 160 when the chamber 8 is emptyof ore, indicates whether or not the chamber is empty.

Said feed screw feeds the ore into the reducing chamber or tube 12,which is constructed of refractory material and inclose l by a metalliccasing 46 of suflicient strength to withstand the gaseous pressuregenerated within the tube, and made in sections held together by bolts17, so as to facilitate its construction and repair and the structurerests on a heavy metallic plate 48, the whole being supported by screws49. Said chamber is cooled by a cooling medium injected through pipes 51and circulates in an annular space around said tube and containedbetween the inner metallic casing 46 hnd an outer metallic casing 52.

Also to facilitate repairs the chamber 12 is made removable, and, when acontinuous operation is desirable, a duplicate chamber is provided, sothat one is always in working order while the other is undergoingrepairs. \Vhen it is desired to remove said chamber, a carriage 53,running on a track 51', and rotatable on a turn-table 56, is run underthe chamber 12. The carriage 53 consists simply of flanged wheelsconnected in pairs by stout axles 57, across which are loosely laidmetallic cross bars 58, which are notched, as shown at 59, to fit overthe axle. To place the carriage under the chamber 12, as shown in Fig.2*, one pair of wheels is rolled up to the side of said chamber, thecross bars 58 being under the bottom of the chamber, and then ends ofthe cross bars are lifted up and the acent notched parts are fitted overthe axle of said wheels. The straps and turnbuclrles 61, 62, 63, whichhold said chamber against the slag hopper 6a and smelting chamber 66,hereinafter described, and against tie ore stack 3 are loosened and theblast and fuel pipes 67, 68, hereinafter described, are raised and swungout of the way on telescope oints 69, 71, thus permitting the chamber 12to be rolled out of the way on the tract: 54:. The chamber 12 is thenraised by means of the screws 49, so that the other ends of cross bars58 may be similarly placed on the axle of the other wheels on theopposite side of the furnace. Said chamber 12 is then lowered and madeto rest shown} In said chamber 73 is a coil of cast iron pipe 76 leadingfrom an air compressor and communicating at the other end with the hotblast pipe 67. Said blast pipe 67 is provided with a valve 77, by whichthe quantity of air passing through said pipe may be regulated orentirely shut off. A branch pipe 79, regulated or shut off by a valve81, leads from the blast pipe 67 to the ore compartment 7. The fuelsupply pipe 68, when oil or gas is used, enters the blast pipe through areducer 83, which 'may be of different sizes, interchangeably used, andvaried according to the fuel used, whether gas or oil. The oil in thepipe 68 is heated by passing the supply pipe through a steamheatedcompartment. To the discharge end of said pipe 68.is connected anatomizer 84 c of any suitable construction which will break up oratoniize the oil as it enters the furnace. The amount of oil entering ina given time is regulated by the pressure on the source of supply andalso by a valve 86.

The lower end of the reducing chamber 12 communicates through a port 87with the smelting chamber 66, which is constructed of refractorymaterial and is provided with a removable cover 88. In the wall of saidchamber 66, next to the reduction chamber 12, is located a slide valve89 made of refractory material, and moved vertically by a screw 91screwed through the top of a standard 92. The object of this slidevalveis to regulate the pressure in the reducing chamber 12 regardless of thequantity of molten metal in the smelting chamber 66, as will hereinafterbe more fully set forth. A spy hole 93 provided with mica windows isplaced in a cover 88. j

The smelting chamber 66 communicates with a settling or collectingchamber 96 through two ports 97 and 98 in the adjacent walls of thesmelting and collecting chambers respectively, and through a port 99 ina. gate 101. Said gate is constructed of refractory material set in ametallic frame 102 provided with tie bolts 103, and raised or lowered bymeans of a screw 104i screwed through a supporting frame 106, whichrests upon the chambers 66 and 96. The ports 97 and 98 in the walls ofthe chambers 66 and 96 are of the same width as the pbrt 99 in thedam orgate 101 but sufiiciently high so as to provide a passage through saidwalls, even when the gate 101 is raisedto its highest position. Underthe port 99 in the gate 101 is located a pipe 107 provided withperforations 108 communicating with the port 98, so that steam, gas orair may be forced into and through the molten matter as it flows throughsaid port. .To prevent overheating of said pipe 107, a cooling medium iscirculated through an adjacent pipe 109, cast in one piece with the pipe107. Finely ground refractoryjmaterial is placed in recesses 111, so asto keep the joints tight be fill! tween the chambers 66 and 96 and thegate 101 at the points where the molten metal flows over from thechamber 66.

In the chamber '96 the metal separates from the slag and settles to thebottom. Said chamber is provided with a door 113 in which is located amica-covered spy hole 114, throu h which the action in the interior maybe observed. Gas and air or superheated steam are conducted by pipes116, 117 connected with suitable sources of supply and may be blown onto the slag-covered metal below, for the purification of said slag, sothat it may be returned to the furnace for fluxing and heating purposes.Waste gases escape by a pipe 110. v

The chamber 96 is placed on rollers 118 in order that it may havefreedom to move somewhat as the parts are expanded through heat, andthus the gate 101 is prevented from being jammed in too tight betweenthe two chambers should they expand. 112'are heavy tension springsfastened adjustably to chambers 66 and 96, and which hold said chamberstogether, pressing against the sides of the gate 101. The chamber 96 isalso provided with metal and'slag outlets 119, 121 (see Fig. 3). 122 isa tap hole at the lowest point of chamber 66 and through which saidchamber may be drained when desired.

By the slag outlet 119 the slag is discharged into a slag truck 123 (seeFig. 3)

' i at truck 123 is elevated by means of a cable which runs on a track124 to a position between standards 126 and guide rails 127c0nnected atthe top bya cross bar 129. The

131 attached to a bail 132, the ends of which are attached to the sidesof the truck, said cable running over a pulley 133 and attached to ahoisting engine (not shown). The truck in its upward movement engagesthe spring-actuated catches 134 having hookshaped portions 136 whichhold down a hinged cover 137 for a slag hopper 64. The engagement ofsaid truck With said catches causes them to be spread apart and to drawthe hooks 136 from said cover. As the truck moves upward, the hookmember 128, extending from the rear end of the truck, engages theabove-mentioned cross-bar 129, stopping the rear part of the truck inits upward movement, tipping the truck, and causing the truck 123 toopen the cover 137. When the truck is sufficiently tlpped, the slag runsout into the hopper 64, and when the slag truck has descended the cover137 again closes and. the spring catches 134 hook over and hold thesame-closed. The slag hopper 64 is provided with a d1scl a1'ge'copduit139 opening into the reductlon chan'l-g ber at substantially the samelevel as the opening thereinto of the ore feeder conduit. Said conduit139 may be closed by agate 141 which is operated by a lever 142supported by a standard 143 and connected to a rod altogether, as isdone when the hopper is being filled with slag. The hopper 64 is linedwith non-conducting refractory material and .is closed to the atmosphereexcept at such times when it is being filled with slag. Into said hopperlead valve-controlled branch pipes 149 and 151, from the fuel and blastmain pipes respectively. The ore stack, slag hopper and the like areerected on the platform 148, preferably of steel girder and reinforcedconcrete construction, said platform and superstructure being supportedon suitable standards 152, the whole being securely fastened togetherand braced. Around the platform extends a suitable hand .rail 153, andthe tie rods 154, which hold the ore stack in position, are securelyfastened, their upper ends to the ore stack and their lower ends to theplatform, said rods being also provided with turn-buckles 156 for theproper adjustment of the rods.

The furnace being first heated up gradually in the usual way, a bath ofmolten metal and flux is supplied to the chamber 66, either bychargingthe material in molten condition into said chamber, or by firstcharging ore and fiux and carbon into the chamber 66 through the top,the cover 88 being removed while this is being done, and then meltingdown the ore and flux in the chamber 66 by the combustion of solidcarbon, such as coke or charcoal. An air blast is supplied through themain 67 and passes down through the chamber 12, but the supply of oil orgaseous fuel may be-diminished or even shut off during the preparationof this bath by the combustion of solid carbon, as heat and reductionare produced thereby. The union of combustible materials under pressure,which takes place when their expansion is resisted, results in increasedchemical action and heat, and, as this invention contemplates thereduction of ores under such conditions, the bath in question isestablished for the purpose of creating and maintaining a resistance tothe flow of the gas through the chamber 12 and also within the bathitself, thereby increasing the pressure of said gas. as the gas has topass through said bath on its way into the chamber 96. It is evidentthat this resistance or back pressure against said gaseous current,moving as stated, will, generally speaking, be in proportion to thedepth of molten matter in the chamber 66. The quantity of molten matterwhich may remain continuously in the chamber 66 is determined by theadjustment ofthe gate 101, and as said gate may be moved up or down, itis seen that as some ores are more refractory than others,

and as fuel oil and gases vary in composition and heating value, theprocess of reduction, in order to become successful and economical, hasto be considered, and the various mechanical adjustments have to beregulated, with these factors in view. Ores of copper, for instance, notrequiring so high a temperature as iron ores to smelt, the resistanceneed not be so high; in other words, the gate 101 may be held'lower, andless depth of molten matter maintained in the chamber 66 in the formercase than in the latter. It is also evident that, where the resistanceto the gaseous current is great, as will be the case when the gate 101is raised, or the gate 89 lowered, and the depth of the molten bath isincreased, a greater amount of fuel and blast, and a greater initialpressure on the same, must be provided in order that said current shallbe able to pass through said bath, there being necessarily a limit ofpressure below which, if the gaseous current is sufliciently resisted inthis direction, its heat would be conducted away through the walls ofthe furnace 'or escape back into the ore stack. What is aimed at is'tomaintain the mass boiling in the chamher 66, and, as the action may beobserved through spy holes 93 in the cover 88, the pressure on the blastand fuel may be regulated accordingly. The pro ortion of fuel to air inorder to produce per ect combustion being known, or since saidproportion in reference to any particular fuel may be determinedexperimentally before it is used in the furnace, the relative amounts offuel and air and the pressure on the same, are determinedcorrespondingly. The initial pres-. sure on an and fuel malns must,however,

in all cases, be sufficiently powerful to overcome the resistance of thebath in the chamher 66 through which the gases have to pass.

The action of the expanding gases in the tube or chamber 12 is somewhatsimilar to that of a solid piston moving against and through the moltenbath in the chamber 66.

T here is this difference, however: Since the gas diffuses in alldirections through the molten bath in the chamber 66, its action,

when it reaches the funnel-shaped entrance to said chamber, is not soviolent or localized as if a solid piston were moving through the bath.Owing to the chamber 66 having a larger cross-sectional area than thatof the chamber 12, the gases are allowed to difiuse I while yet in themetal, but, as it is the depth of the molten bath in the chamber 66 overand above the point where the gases enter saidv chamber, and not itshorizontal area, that determines the resistance and heating value ofsaid bath, these factors are kept in mind in the construction of thefurnace. The cross-sectional areas of the chambers 12 and 66, as shown,are as 1 to 10 respectively, this being a convenient not wish to limitmysel to this proportion, seeing that the same depth of bath may be keptin a chamber proportionally larger than the one here shown. The gaseouspressure in the chamber 12 may also be increasedregardless of the depthof the molten'bath in the chamber 66, this being accomplished bylowering the gate 89. There must, however, always be a sufiicient amountof molten matter in the chamber 66 so that the gases must ass throughthe same in their progress rom the chamber 12 to the chamber 66. As theinner walls of the chamber 66 taper gradually, reducing thecross-sectional area of said chamber until itbecomes equal to that [ofthe chamber 12 at the junction of the two chambers, it will be seen thatthe gases diverge from the point of junction. In this manner will thewhole of the molten bath in the chamber 66 be moved and acted upon bythe hot expanding gases from the chamber 12 diffusing through the mass.

Having prepared the bath in the chambe 66, as stated, and of a depthsuiiicient to close the port between the chambers 12 and 66' and toextend above said port about twelve inches, I open the valve to the fuelmain so as to admit the proper mixture of gas or gasified oil and airunder pressure into the chamber 12. The feedscrew 27 is now set inmotion on slowest speed so as to force material from the ore compartment7 into the chamber 12.

The slag hopper 64: having been filled with the same material as isprepared in the chamber 66, or, if preferred, with a molten fluxprepared separately, this material is now also admitted to the chamber12 by opening the gate 141. The speed of feed'in the ore into thechamber 12 is determine by the speed-of reduction, and this is ascertained by noting the boiling in the chamber 12 and also by examiningsamples of the molten material as it flows into the chamber 96, Thespeed of the feed screw 27 is regulated by dlfi'erentialspe'ed mechanism38 or equivalents. The amount or flow or flux is regulated by raising orlowering the gate 141 and is otherwise roportioned to the ore charged,but, as this ux is" used in a molten condition, it wil be seen that itsheatpas well as its chemical composition, aids in the re duction of ore,and the only drawback, therefore, tothe use of a liberal allowancecontinuously is that the slag hopper 59 has to be replenished oftener. I

Should the material, when the process is fully established, be found toboil violently, reduce well, and run freely into the chamber 96, underslight initial ress ure on fuel and air, this indicates that may speedupthe process by raising the gate 101, forcing in. the-ore faster, andadmltting more blast and fuel under greater pressure. On the, otherhand, should the material in the cham ber 66, fed in slowly, as beforementioned, not a pear to reduce well and flow into the chamber 96freely, then this is an indication of a refractory ore requiringmoreheat' and a" somewhat longer treatment for reduction.

In such case, the dam 101 is raised, so as to providafor adeeper bathand more resistance to the current, the fuel and blast supply beingregulated to suit this condition, that is, to cause'a brisk boiling ofthe mass, but the charging of ore is not increased under thesecircumstances.

A small quantity of solid'carbon is added to the ore charged, all beingin. pulverized form. Said carbon, being in finely divided state, isimmediately heated to incandescence as it enters the reduction chamber12, and,

in this condition, it unites with the oxygen of the steam formed throughthe combustion of the hydro-carbons supplied. The gases are thus kept inthe necessary reducing condition throughout said chamber, and thiscondition is further enhanced as said gases are forced through thepermanent molten bath. in the chamber 66. As both CO and CO may beneutral to molten iron provided the temperature of the above-mew tionedgasesand-the bath through which they pass is sufiiciently high, thishigh temperature is produced by the high gaseous pressure in the chamber12 and the resistance to the gaseous current maintainedby the moltenbath in the chamber 66. The

greater the initial pressure and resistance, as before mentioned, thegreater will be the heat in the elements involved, and the less freecarbon is necessary to maintain a reducing atmosphere toward the oxid inthe chamhere 12 and 66, and the less carbon will there involved in theprocess are preferably kept in separate bins, placed so as todeliverinto the moving conve'yer buckets through spouts provided withadjustable shutters, it is seen that the various ingredients ofthecharge, both as to fluxing and carbon content, may readily be changed.as occasion requires. The speed of delivery of said material into theore stack may be regulated by any well known differential speedmechanism arranged on the axle of the drum which carries the belt onwhich the conveyer buckets are placed. Said speed may also be regu- Asthe materials same a reducing gas, said gas being supplied through thepipe 107 in the dam 101, said gas being forced through the small holes108 into and through said molten matteilas this flows over into thechamber 96. ir and superheated steam are forced through pipes 116, 117on to the accumulating slag and metal in'the chamber 96 and the objectof this treatment is in the main to purify the slag so as to make itfitto return to the furnacefor fluxing purposes. Should it be necessaryto further heat the slag in the hopper 64, this may be done by means ofa lighted burner projecting into said hopper and supplied from the fueland air mains 149 and 151. Before opening the cover gon the hopper 64 inorder to charge the same, the grate 101 is closed by raising the rod1&4, said rod acting on the lever 142 and on the gate 141 to close thesame. this is to relieve the'cover of the interior pressure before it isopened. 7

The movement of the material in the stack 3 and the operation of theslides 9 and 11 are as folloWs:--The conveyor being in motionand-supplied from suitable" bins, as

mentioned, with the pulverized material to be treated, the slides 9 and11 are open sobegins.- The slides 9 and 11 are opened and closedalternately, in order to prevent the pulverized material and ases fromblowing out through the stack. l hus while the slide llis closed, theslide'9 is open, until the com .artment 6 is filled, or until the supplyin t e compartment 7 has run down, as

shown by the indicator 150, then the slide 9 is closed and the slide 11opened so that the. material in the compartment 6 may descend into thecompartment 7. This being done, the1 slide 9 is again closed to begin anew cyc e. v

The speed of ore deliver into the chamber 12 is determined mec anicallyby the differential speed mechanism, and' otherwise by the rapidity ofthe reduction which is taking place,*as previously mentioned, care beingtaken not to charge ore faster than it is reduced. Brisk boiling in thechamber 66 and a regular overflow of molten reduced matter into thechamber 96 indicate re lar workin The mechanism involved eing adjustale, both as to supply of fuel and air, the initial pressure on the same,the

The object lof speed of the feed screw and the depth of thepressure-producing bath in the chamber 66, all these factors are to beconsidered together, with reference to. the nature of the ore treated,in order that a successful reduction of the same may be obtained. Shouldit be desired to change from liquid to gaseous fuel or vice versa, thismay readily be done by change of supply pipe, the connection 83 in theblast main being of sufficiently large outside diameter to admit pipesof difierent sizes, such as may be required for different fuels. At thetime of tapping the furnace, or oftener if necessary, the hopper 64 isreplenished with molten slag from the chamber 96 by means of the slagtruck 123 and accessories, as shown. The pressure on the blast and fuelis produced and gaged in the usual way, being further re ulated as toamount by valves, as shown. S ould it be desirable to maintain a moreoxidizing atmosphere in the chamber 12 than is otherwise produced, thevalve 81 on the branch 7 9 of the blast pipe is opened, thus admittingair to the compartment 7, said air forcing its way into the chamber 12and producing the afore-mentioned effect.

In the reduction and smelting of oxide of iron or ores of a similarnature, it is necessaryv to maintain a hot reducing atmosphere in thefurnace. nature of the fuel where solid carbon is used exclusively inthat a large part of the gases generated by the use of such fuel will remain sufiiciently reducing, where enough fuel is supplied to 'deoxidizethe ore and reduce it to metal, even thou h atmospheric air be freelyadmitted. Wlrere hydrocarbons, or gases containing a considerableportion of hydrogen, are used in furnaces of the ordinary construction,the action is somewhat different in that the atmosphere produced is moreoxidizing than in the former case, especially so in reference to oressuch as mentioned.

Various expedients, such as electric heating or heating of the gasesprior to their in ection into the furnace have been suggested, orresorted to, in order to produce the desired effect, but so far as Iknow, without any practical success.

My invention contemplates the production and maintenance of thenecessary reducing character of the hydrocarbons involved and otherfeatures for the purpose stated First. By manipulating the gasesinvolved in a reduction chamber so constructed and operated that theatmosphere of the entire chamber may be maintained uniform, said chamberbeing practically closed to the outside air.

Second. By admitting air and gas or atomized oil into the reductionchamber of the furnace under pressure-and maintaining a certain pressurewithin said chamber.

This is provided for by the 'in conjunction with suitable fluxinf Third.By the immediate superheating of the gases as they come in contact withthe incandescent walls of the reduction chamber, the construction ofsaid chamber being such as to admit of close contact with the gases.

Fourth. By the introduction of molten flux or slag into the reductionchamber where the gases and other material involved mix and come inintimate contact with said slag.

Fifth. Through the dissociation of the steam formed by means of thepulverized solid carbon of the charge as mentioned, since said carbon,being in a finely divided state, is immediately heated as it enters thereduction chamber, sufliciently to cause said dissociation.

Sixth. By the further heating and carbonization of the gases involved asthey are forced through the molten bath in the chamber 66.

Seventh. By the establishment and maintenance of acontinuouslyincreasing reductive action in the elements involved as theyare moved under pressure against the resistance' of the molten bathinthe chamber 66.

Eighth. By causing all the elements involved in the process to travel inthe same direction through the furnace in gaseous and finely dividedstate and under pressure, thus insuring intimate contact, rapidreduction and chemical combination of said elements.

Ninth. By causing the gaseous elements involved to pass through acertain depth of molten matter containing a metal, thus superheating andboiling said matter to the extent that disassociation and recombinationmay take place of the gases and metallic elements respectively.

Tenth. By such construction 'of the furnace that there shall be, withinthe reduction chambelyof the same, a space practically closed to theoutside atmosphere, and through which space all the elements of theprocess may travel freely under pressure toward a molten bath forming aseal to said chamber, and through which bath the gases 'involved aremade to pass.

In the operation of my invention I donot wish to confine myself to thereturn of slag only to the furnace as mentioned, for, in certaininstances, it may be more advantageous to return a partly reduced metal,or matter in molten condition, which then acts elements in the charge toproduce the esired results. -As the molten slag acts not only as aflux'but also as a heating agent to quickly fuse the ore and keep it inmotion, it is evident that, where proper fluxes are added to the charge,any other part of said charge in molten condition will act in theabove-mentioned capacity as well as the slag, and the 1,ses,ua

operation thus modified will have a concentrative effect on the metalinvolved, as, for instance, in cop er smelting. If, for any reason, itshould anything through the slag hopper into the furnace, said hoppermay be closed by shutting the gate 141 asbefore mentioned. As the moltenmatter accumulates in the chamber 66, it runs over into the chamber 96where metal and slag Separate and rare tapped as occasion requires.

11 case solid carbon is used exclusively as fuel it is fed into thereducing chamber by means of the feed screw 27.

By the term purified slag as herewithin used is meant a slag from whichphosphorus and sulfur have been separated by forcing gaseous oxidizingagents on to the slag whlle it has been maintained in a molten conditionand preferably resting on a metallic bath.

I claim 1. An ap aratus comprising a furnace having a re ucing chamber,means for feeding ore and fuel into said reducing chamber, means forsupplying compressed air thereinto, means for preventing the free escapeof gas therefrom, a smelting chamber and a communication between it andthe reducing chamber so constructed that a liquid resist ance tocompressed gases may be maintained between said chambers.

2. An apparatus comprising afurnace having a reducing chamber, an orestack, the inner portion of which is closed to the external atmospherebut always incommunication with the furnace, means forfeeding ore fromthe stack and fuel into said reducing chamber, means for su plyingcompressed air thereinto, a sme tlng chamber and a communication betweenit and the reducing chamber so constructed that a liquid resistance tocompressed gases may be maintained between said chambers.

3. An apparatus comprising a furnace having a reducing chamber, meansfor feeding ore and fuel into said reducing chamber,

means forsupplying compressed air there-. into, means for preventing thefree escape of gas therefrom, a smelting chamber and a communicationbetween it and the reducing chamber so'constructed that a liquidresistance to compressed gases may be maintained between said chambers,and means for varying the size of said communication.

4. An apparatus comprislng a furnace having a reduced chamber, means forfeeding ore and fuel into said reducingchamber, means for supplyingcompressed air thereinto, means for preventing the free escape of gastherefrom, a smelting. chamber and a communication'between it and thereducing chamber and so constructed that a liquid re: sistance tocompressed gases may be maintained betweefi said chambers, means for bedesirable not to charge varying the size of said communication, andmeans for varying the depth of said resist.- ance.

5. An apparatus comprising a furnace having a reducing chamber, an orestack, the inner portion of which is closed to the external atmospherebut always in communication with the furnace, means for feeding ore fromthestack and fuel into said reducing chamber, means for indicating thequantity of ore in said stack, means for supplying compressed airthereinto, a smelting chamber and a communication between it and thereducing chamber so constructed that a liquid resistance to compressedgases may be maintained between said chanibersl 6. An apparatuscomprising a furnace having a reducing chamber, an ore stack, the

inner portion of which is closed to the external atmosphere but alwaysin communication with the furnace, means for feeding ore from the stackand fuel into said reducing chamber, revoluble means for indicating thequantity of ore in said stack, means for supplying compressed airthereinto, a smelting chamber and a communication between it and thereducing chamber so constructed that a liquid resistance to compressedgases may be maintained between said chambers.

, 7 An apparatus comprising a furnace having a reducing chamber, meansfor feeding ore and fuel into said reducing chamber,

means for supplying compressed air there-- into, means for preventingthe free escape of gas therefrom, a smelting chamber and a communicationbetween it and the reducing chamber so constructed that aliquidresistance to'compressed gases may be maintained between saidchambers, said reducing chamber being removable frommthe smeltingchamber. l

48. An apparatus comprising a furnace having a reducing chamber, meansfor feeding ore and fuel into said chamber, means for supplyingcompressed air, thereinto, means for preventing the free escape of gastherefrom, a smelting chamber, the reduction chamber being removablyattached to the smelting chamber and the smelting chamber and reductionchamber communicating with each other, the communication being such thata liquid resistance to compressed gases may be maintained between saidchambers, a settling chamber flexibly attached to and in communicationwith said smelting chamber and means for injecting steam and air uponthemolten material in said settling chamber.

' 9. "A reducing and smelting apparatus having a chamber closed tothe'external atmosphere, means for continuously and simultaneouslypassing fuel, air, and material to be treated through said chamber,means for forming and malntaining a liquid resistance in said chamber,means for forcing gases under pressure through said resistance and ma.

terial to be treated into said resistance, means for predetermining thepressure in said chamber, and means for drawing off the materialtreated.

10. An apparatus comprising a furnace having a reducing chamber, meansfor feed ing ore and fuel into said reducing chamber, means forsupplying compressed air thereinto, means for preventing the free escapeof gas therefrom, a smelting chamber and a communication between it andthe reducing chamber, so constructed that a liquid'resistance to thepassage of compressed gases may be maintained between said chamber, andmeans for establishing resistance, a settling chamber flexibly attachedto, and having communication with, said smelting chamber, means toadjust said communication and means whereby gases may be forced throughthe molten material as it flows through said communication.

11. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other.

12. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means formaintaining the resistance in a definite position relative to the twochambers.

13. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand thronghwhich they can communicate with each other, and means formaintaining said resistance at a constant level.

14. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means formoving into the material offering the resistance the material to betreated.

15. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,and means for automatically regulating the rate of supply of material tosaid resistance.

16. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material ofi'ering the resistance the material to be treated,

and means for adding material as desired to the resistance.

17. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means formoving heated reduced material into the material otlering theresistance.

18. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,and removable means for preventing the material in the resistance cominginto contact with the outside atmosphere.

19. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,and means for superheating the molten matter in the resistance.

20. An apparatus comprising a furnace having reducing and smeltingchambers constructed to form a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,said re ducing chamber being closed to the external atmosphere wherebysaid gases are heated.

21. An apparatus comprising a furnace having reducing and smeltingchambers constructed to form a liquid resistance to the passage of gasesand'through which theycan communicate with each other, means for movinginto the material ofiering the resistance the material. to-be treated,

means for producing pressure by a hot gas on said resistance, and meansfor varying said pressure.

22. An apparatus comprising a furnace having reducing and smeltingchambers constructed to form a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,means for producing pressure by a hot gas on said resistance, and meansfor maintaining the pressure on the resistance constant notwithstandingvariations inthe amount of material fed into saidreducing chamber.

23. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,means for producing pressure by a hot gas on said resistance, and meansfor maintaining the pressure within the resistance constantnotwithstanding variations in the amount of material fed into saidreducing chamber.

24. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistvance the material to be treated,and means for forcing gases through the resistance.

25. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means "formoving into the material offering the resistance the material tobetreated, and means for diffusing said gases through the molten matterof the resistance.

26. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means forvarying the level of the resistance.

27. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,means for difiusing said gases through the molten matter of theresistance, and means for bringing the gases toa reducing conditionbefore they enter the resistance.

28. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquidresistance to the passage of gasesand through which they can communicate with each other, means for movinginto the material oflering the resistance the material to be treated,means for diffusing said gases through the molten matter of theresistance, and means for maintaining a reducing condition of theelements in contact with, and entering, the resistance. r

29. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold -a liquid resistance to the passage ofgases and through which they can communicate with each other, means formoving into the material offering the sistance the material to betreated, means for difiusing said gases through the molten matter of theresistance, and means for car bureting' the gases before they enter the-re+ sietance.

32. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance. to the passage ofgases and through which they can communicate with each other, and meansfor causing ebullition of the molten matter constituting the resistance.

33. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means forpreserving the gases escaping through the material offering theresistance.

34:. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, means fer movinginto the material offering the re.- sistance the material to betreated,means for diffusing said gases through the molten matter of theresistance, and means for reducing the overflow from the resistance.

35. An apparatus comprising a 'furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage ofgasesand through which they can communicate with each other, means for movinginto the material offering the resistance the material to be treated,means for diffusing said gases through the molten matter of theresistance, means for main taining a reducing condition of the elementsin contact with, and entering the resistance, means for purifying slagoverflowing from the resistance, and means for conveying said purifiedslag to a point convenient for dis charging it into a succeeding body ofma terial to be treated. I

36. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means forseparating slag and metal flowing from the resistance.

37. An ap aratus comprising a furnace having reducln and smeltingchambers con etructed to ho d a liquid resistance to the passage ofgases and through which they constructed to hold a liquid resistance tothe passage of gases and through which they can communicate with eachother, and means for blowing gases on to the surface of material whichhas passed through the resistance.

39. An apparatus comprising a furnace having reducing and smeltingchambers constructed to hold a liquid resistance to the passage of gasesand through which they can communicate with each other, and means fordraining the resistance.

40. In an apparatus for the reduction and smelting of ores, thecombination of a reduction chamber, a smelting chamber and a settlingchamber, means in said settling chamher for the purification of metaland slag and means for the return of said purified molten slag to thereduction chamber for fluxing and heating purposes.

41. In an apparatus for the reduction and smelting of ores, thecombination of a reduction chamber, a smelting chamber, and a settlingchamber, means in said settling chamber for the purification of moltenmetal and slag, means for the return of said purified molten slag to thereduction chamher and means communicating with said reduction chamberwherein said purified molten sla may be stored.

42. ii an apparatus for the reduction and smelting of ores, thecombination of a reduction chamber, a liquid resistance in a smeltingchamber and a settling chamber, means in said settling chamber forblowing air and steam on the molten material in the same, means for thereturn of said molten slag to the reduction chamber, means for holdingsaid slag and adjustable means for regulating the flow of said moltenslag into the reduction chamber.

43. in an apparatus for the reduction and smelting ofores, thecombination of a reduction chamber, a smelting chamber, a Eiquidresistance in said chamber, a settling chamber, adjustable means betweensaid settling and smelting chambers forming a communicating port betweensaid chambers, means for forcing gases through the molten material. asit blows through said port, means for blowing steam and air into themolten material in the settling-chamber, means'for the return of themolten slag to thereduction chamber, means in communication with saidreduction chamber for storing said molten slag and means for regulatingthe dew of said blown molten slag into the reduction chamber.

ae. in an apparatus for the reduction and smelting of ores, thecombination of a reduction chamber, a smelting chamber, a liquidresistance to gases between the two chambers and a settling chamber,means adjacent to said settling chamber for the blowing of gases throughthe molten material flowing into said chamber, means for blowing air andsteam into the molten slag and metal in said chamber, means for thereturn of the blown slag to the reduction chamber, means incommunication with said chamber to hold said slag, adjustable means forregulating the flow of said slag into the reduction chamber, and meansfor keeping said slag in a heated molten condition prior to its enteringthe reduction chamber.

45. In an apparatus for the reduction and smelting of ores where theslag resultant from the process is purified and used repeatedly as aflux, the combination of a reduction chamber, a smelting chamber, a

liquid resistance to the passage of gases between said chamber, asettling chamber, adjustable means forming a communicating port betweensaid settling chamber and the smelting chamber, means whereby gases maybe blown through the molten material flowing through said port, meansfor blowing air and steam into the molten slag and metal in saidsettling chamber, means for the return of the blown molten slag to thereduction chamber, means in communication with said reduction chamber tohold said molten slag, adjustable means for regulating the flow of saidslag into the reduction chamber, means for keeping said slag in a heatedmolten condition prior to its entering said reduction chamber, meanswhereby a pressure at least equal to that within the reduction chamberof'said apparatus may be maintained within said slag holdingcommunicating means, and means for releasing the aforesaid pressure.

46. in an apparatus for the reduction and smelting of ores, thecombination of a reduction chamber, a smelting chamber, a liquidresistance between said chambers, and a settling chamber, means fordraining" said chambers and resistance and means for moving,substituting and making ready repairs to said chambers.

47. In an apparatus for the reduction and smelting of ores, a reductionchamber, a

smelting chamber, a liquid resistance be tween said chambers and asettling chamber, and flexible means to compensate for expansion andcontraction connecting said smelting and settling chambers.

48. In apparatus for the reduction and smelting of ores, a reductionchamber, a liquid resistance to the passage of gases, a smeltingchamber, constructional means in the reduction chamber whereby the fuelinvolved may be quickly heated to incandescence comprising a verygradually flar- 49. The method of reducing and smeltingores whichconsists in first smelting the ores and maintaining the smelted ores insuch form as to offer a liquid resistance to the passage of gases,passing gases through said liquid resistance, and carburizing thematerial ofthe resistance.

50. The process of reducing ore which consists in feeding the ore into aclosed chamber, supplying fuel and compressed air to said chamber toreduce and melt the ore, preventing the escape of gases from the feedend of said chamber, maintaining at the discharge end of said chamber acolumn ofmolten ore of a suflicient height to oppose the escape of gasesat said dischargeend, and drawing off the molten ore at said dis chargeend.

51. An apparatus comprising a furnace having reducing and smeltingchambers constructed to operate by the use of fluid fuel and to hold aliquid resistance to the passage of gases, through which liquidresistance they can communicate with each other, said reducing chamberbeing provided with means whereby the fluid fuel passing therethroughmay gradually expand'and be highly heated and maintained in the reducingcondition before coming into contact v with the ores tobe treated.

52. The process-of reducing ore which consists in feeding the ore into aclosed chamber, supplying fuel and compressed air to said chamber toreduce and melt the ore, preventing the escape of gases from said feedend of said chamber, maintaining at the discharge end of said chamber acolumn of moltenore of a sufficient height to oppose the escape of gasesat said discharge end, drawing off the molten material, and utilizingthe heated slag as a flux and to heat the reducing chamber.

53. The process of reducing ore which consists in continuously feedingthe ore into a closed chamber, supplying fuel and compressed air to saidchamber to reduce and melt the ore, preventing the escape of gases fromthe feed end of said chamber, maintaining at the discharge end of saidchamber a column of molten ore of a sufiicient height to oppose theescape'of gases, and drawing 0d the molten material at. said dischargeend.

54. The process of reducing ore which" consists in feeding theore intothe upper end of a vertical chamber having a liquidseal, supplying fueland compressed air at the same end as the ore to said chamber to 'retimeand melt-the ore, preventing the escape of gases from the feed end ofsaid chamber, maintaining at the other end of said chamber a column ofmolten ore of a sufiicient height to prevent the escape of gases at saiddischarge end, and drawing off the molten material at said other end.

55. The process of reducing ore which consists in feeding the ore into aclosed chamber, supplying fluid fuel, .acir, solid carbon and moltenslag to said chamber to reduce and melt the ore, and drawing off themolten material.

56. The metallurgical process which consists in forcing hot gases underpredetermined pressure and of predetermined carbon content through afurnace chamber and through a molten bath of metalliferous material andflux, said bath, forming a" seal to said chamber, supplying additionalmaterial to said bath to facilitate chemical action in the same, andwithdrawing the excess of said molten material.

57. In metallurgical processes, the steps which consist in forcingoxidizing gases on to slag produced in said processes while said slag ismaintained in a molten condition and resting on a metallic bath, andreturning said molten slag in a purified condition to the furnace forheating and fluxing purposes.

58. The method of reducing and smelting ores which consists in forcingsaid ores into and through a furnace chamber filled with reducing gasesunder pressure, said gases being heated by the resistance of a moltenbath through which they must pass and into contact with which bath saidores are carried.

59. The method of reducing and. smelting ores which consists in movingall the material involved in the same direction in a gaseous or finelydivided state through a reducing chamber sealed to the outsideatmosphere, an automatically regulated gaseous pressure being maintainedin said chamher, said gases under pressure being made to pass intoanother chamber through a molten bath.

a 60. The process which consists in forming and maintaining a 1i uidresistance to the reducing throughouuand under airegulated gaseouspressure, employing said pressure to move the ores into contact with amolten bath in the smelting chamber, and confining the molten bath toform a liquid seal between the two chambers.

62. The continuous method of reducing and smelting granulated ores withhydrocarbons or gaseous fuels which consists in forcing said ores and aregulated amount of flux into and through a highly heated reductionchamber under a predetermined pressure into a molten bath in which baththe ore and flux are agitated by the ebullition of the gases assingthrough the same.

63. he continuous method of reducing and smelting granulated ores withhydrocarbons or gaseous fuels which consists in forcing said ores andpurified heated slag into and through a highly heated reduction chamberunder a regulated pressure into a molten bath in which bath the ore andslag are maintained in ebullitio'n by the gases passing through same.

fi l. The continuous method of reducing and smelting finely divided oresunder blast pressure by the use of liquid fuel which consists in forcingsaid-ores, a small amount of carbon, and a molten dun into and through ahighly heated reduction chamber into contact with a purified moltenslag.

65. The process which consists in forming a metallic bath in a furnacechamber by means of metalliferous material smelted with solid carbon,maintaining said bath of sufiicient depth to form a liquid resistance tothe passage of gases through said chamber, feeding metalliferousmaterial and flux into said bath, forcing hot carbureted -gases throughsaid bath to reduce, smelt and carburize said material, and drawing offthe excess of molten material.

66. The process of reducing ores which consists in feeding the ore intoa closed chamber, supplying fuel, air, solid carbon and molten purifiedslag to said chamber to reduce and melt the ore and drawing off themolten material.

67. The process of reducing ore which consists in feeding the ore into aclosed chamber supplying fiuid fuel, air, a small amount of pulverizedcarbon, molten purified slag and material to chemically qualify saidmolten slag for during purposes, to reduce and melt the ore and drawingofi the material.

68. The process of reducing and smelting finely divided ores under agaseous pressure, which consists in feeding said ores into and through aclosed reduction chamber filled with highly heated gases underpredetermined pressure commingling said ores in their passage throughsaid chamber with a molten purified slag fed simultaneously therein,moving said ores, molten slag and gases into and through a bath ofmolten metal and slag to reduce and melt said ore and drawing off themolten material.

69. The process of reducing and smelting ores which consists in movingall the induced being purified by forcing suitable gases through thesame as said metal and slag passes through said aperture.

v 70. The process of reducing and smelting ores which consists in movingsaid ores, a highly heated purified molten slag, material to chemicallyqualify said slag for fiuxing purposes and the fuel involved into andthrough a reduction chamber filled with highly heated gases underpressure, the reducing quality of said gases being further augmented bythe addition of a small amount of pulverized carbon; said material beingfurther moved into contact with and through a bath of molten metal andslag to smelt said ore, the metal and slag produced being still furthermoved through an adjustable aperture into a settling chamber, a suitablegas bein forced through said metal and slag in their passage throughsaid aperture for purification purposes.

71. The process of reducing and smelting ores which consists incommingling and moving in the same direction all the elements of thecharge and the gases involved into and through a reduction chamberfilled with highly heated carbureted gases under pressure, said pressurebeing adjustable from both ends of the reduct1on chamber, said chargeand the gases involved being further moved into contact with and througha bath of molten metal and slag to smelt the ore, the metal and slagproduced" being still further moved through an aperture adjustable inreference to the depth of said bath and into a settling chamber, the

molten metal and slag being blown. in passage by a suitable gas andstill further blown with steam and air in said settling chamber.

72. The -method of treating ores which consists in causing the ores andfproducts thereof to flow in a continuous stream, continuously feedingores at one end of said stream, continuously drawing away the productsfrom the other end thereof, reducing and smelting the ores in oneportion of said stream and simultaneouslypurifying the molten metal andslag derived from ores in another portion of said stream.

73. In a process which includes the heating of metalliferous material,the step which consists in adding to said material purified molten slag,and fluxing and heating thereby,

sesame "M, la processes which include lithe heating of metalliferousmaterial, the seeps Which consisa in repeatedly purifying, chemicallyualifyirig; and returning to saiol processes it e slab; produced andheating thereby.

75. he methocl of reducing and smelting ores which consists in feedingsaid ores, molten slag, material to increase the firming properly ofsaid slag, and "the necessary fuel ln'lo a compressed heated reducing[atmosphere in a chamber having a liquid seal, ancl gradually expanding,gasilying, heating aml mains-aiming in reducing condition the said iiuel in said chamber before said fuel comes iii. comfiaol, with said ore:

78. eoriifiinaous methorl of reducing and sreeliaiagg by use oi fluidluel which consists in feeding said fuel, finely rliviclecl ores andgranulated carbon into a com pressed, healed reducing atmosphere "withina chamber having a liquid seal and. cans ing said fuel to graduallyexpand, to be fully gasiiieol and to be highly heated and maintained inreducing condition in said. chamber before coming into Contact with saidores. I

In testimony whereof I have hereunto set my hand in the Witnesses.

JOEL LUND.

Witnesses: I M. rarer-m Do llreeseesu presence of'two subscribing

